Recent years have seen an increase in interest in using an EC (E-commerce; Electronic Commercial Transaction) site to perform commercial transaction operations across different countries (so-called “International EC”). JP2013-235407A discloses a logistics information system for making customs work proceed smoothly while preventing falsification of private imports. In the same system, first, if a product purchase has been secured on an EC site in response to a request from a user, inspection of the product and calculation of tax rates is performed on an intermediary agent terminal. The result of the inspection and information regarding the tax rate is transmitted to a server, and billing information for payment of expenses to which user administration and tariffs have been added is generated in the server. The billing information is transmitted to a user terminal and the intermediary agent terminal. Upon confirming payment made by the user, an intermediary agent dispatches the product and pays for tariffs on behalf of the user.